Investigators Award of the Belgian Society of internal Medicine location:Leuven date:4-5 December 2009
Background: Currently 80-90% of patients treated with daily therapeutic plasma exchange (TPE) survive the initial episode of thrombotic thrombocytopenic purpura (TTP). However relapses occur in substantial fraction of patients. To date, there are no randomized clinical trials to provide data for long-term management decisions. The decision to stop or continue treatment is essentially still empirical.
Aim. The study aimed ad documenting current therapeutic medical practice for TTP and response to treatment in one Belgian University Hospital.
Methods. Medical records were used for this retrospective observational study. Statistical analysis was purely descriptive.
Results. 12 patients with 18 documented episodes were included. Renal and neurological dysfunction were reported in 61% and 33% of the episodes. At baseline platelets and LDH were abnormal in 17, creatinine in 11 episodes. TPE was used in all cases. In 12 episodes adjunctive therapy was given. The mean number of TPE procedures/episode was 18. The number of plasma volume exchanged per dag (PE/PV) ranged from 0.1 to 1.5, with a mean patient PE/PV of 1. The outcome of the TTP episodes reported here was: complete remission (CR) in 9, partial remission (PR) in 6 and death in 3 cases. Among the episodes classified as CR<, 2 relapses were observed. Normalization of platelets and lactate dehydrogenase took an average of 13.1 and 8.1 days respectively, corresponding to 12 and 7.4 TPE procedures. Renal an neurological normalisation was reached after 11 and 5.3 days respectively, corresponding to 10 and 4.7 TPE procedures. On average, relapses (6 to 4 patients) occurred 85 days after last treatment of the previous episode.
Conclusion. We performed a retrospective single center study analyzing current therapeutic medical practice for TTP. With this small study we hope to offer a platform for large observational studies to identify the benefit of particular treatment schedules, to define a relevant treatment algorithm, to identify factors of poor prognosis and to determine the place of adjunct therapies. Long-term clinical follow-up studies on the outcomes of patients after recovery from an acute episode of TTP are necessary to document the risk for relapse as well the occurrence of long term complications.